Case study: River Tees

The River Tees is located in the north of England. The source of the River Tees is located in the Pennines and it flows east to its mouth where the river joins the North Sea.

Upper course

• The upper course has hard impermeable rocks. Here, vertical erosion has formed a V-shaped valley.
• High Force, the UK's largest waterfall at 21 metres high is located in the upper course. An area of hard rock, called Whin Sill (or Whinstone), is located above a layer of soft rocks (sandstone and shale) and together they create this impressive waterfall.

High Force waterfall

Middle course

• As the River Tees starts to erode sideways (lateral erosion), it forms meanders. These can be identified in the middle course near Barnard Castle.

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Lower course

• Near Yarm, the meanders in the lower course are much larger, and oxbow lakes have formed. In this area there are also levees which have formed when the river has flooded.
• The River Tees has a very large estuary with mudflats and sandbanks which supports wildlife in the area. Sites such as Seal Sands are protected areas.

The River Tees estuary and its mudflats